There are known methods of out-of-furnace steel-refining, wherein the establishment of a vacuum in the ladle is used in combination with AC arc-heating (ASEA-SKF Finkle et al-processes) with simultaneous gas or electromagnetic stirring of the melt inside the ladle. Another version of induction heating has also been developed (IT-process). The basic shortcoming of these methods is the prolonged treatment cycle due to the interruptions between the degassification-processes employing vacuum conditions, the electric-arc heating and the desulfurization all conducted as independent steps.
Devices, using vacuum-type systems together with AC-arc or other types of heating of the metal melt inside the ladle use two or more sequentially located stands for the vacuum and heating systems, each stand having an appropriate device for the stirring of the melt.
The simultaneous and successive uses of vacuum and AC-arc heating is linked to a complicated design of the roof or the upper part of the vacuum chamber to rapid wear of the lining and to high consumption of electrodes.